| /* |
| * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks |
| * |
| * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. |
| * |
| * This file is released under the GPLv2. |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/io.h> |
| #include <linux/pm.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/clk.h> |
| #include <linux/slab.h> |
| #include <linux/err.h> |
| |
| #ifdef CONFIG_PM_RUNTIME |
| |
| struct pm_runtime_clk_data { |
| struct list_head clock_list; |
| struct mutex lock; |
| }; |
| |
| enum pce_status { |
| PCE_STATUS_NONE = 0, |
| PCE_STATUS_ACQUIRED, |
| PCE_STATUS_ENABLED, |
| PCE_STATUS_ERROR, |
| }; |
| |
| struct pm_clock_entry { |
| struct list_head node; |
| char *con_id; |
| struct clk *clk; |
| enum pce_status status; |
| }; |
| |
| static struct pm_runtime_clk_data *__to_prd(struct device *dev) |
| { |
| return dev ? dev->power.subsys_data : NULL; |
| } |
| |
| /** |
| * pm_runtime_clk_add - Start using a device clock for runtime PM. |
| * @dev: Device whose clock is going to be used for runtime PM. |
| * @con_id: Connection ID of the clock. |
| * |
| * Add the clock represented by @con_id to the list of clocks used for |
| * the runtime PM of @dev. |
| */ |
| int pm_runtime_clk_add(struct device *dev, const char *con_id) |
| { |
| struct pm_runtime_clk_data *prd = __to_prd(dev); |
| struct pm_clock_entry *ce; |
| |
| if (!prd) |
| return -EINVAL; |
| |
| ce = kzalloc(sizeof(*ce), GFP_KERNEL); |
| if (!ce) { |
| dev_err(dev, "Not enough memory for clock entry.\n"); |
| return -ENOMEM; |
| } |
| |
| if (con_id) { |
| ce->con_id = kstrdup(con_id, GFP_KERNEL); |
| if (!ce->con_id) { |
| dev_err(dev, |
| "Not enough memory for clock connection ID.\n"); |
| kfree(ce); |
| return -ENOMEM; |
| } |
| } |
| |
| mutex_lock(&prd->lock); |
| list_add_tail(&ce->node, &prd->clock_list); |
| mutex_unlock(&prd->lock); |
| return 0; |
| } |
| |
| /** |
| * __pm_runtime_clk_remove - Destroy runtime PM clock entry. |
| * @ce: Runtime PM clock entry to destroy. |
| * |
| * This routine must be called under the mutex protecting the runtime PM list |
| * of clocks corresponding the the @ce's device. |
| */ |
| static void __pm_runtime_clk_remove(struct pm_clock_entry *ce) |
| { |
| if (!ce) |
| return; |
| |
| list_del(&ce->node); |
| |
| if (ce->status < PCE_STATUS_ERROR) { |
| if (ce->status == PCE_STATUS_ENABLED) |
| clk_disable(ce->clk); |
| |
| if (ce->status >= PCE_STATUS_ACQUIRED) |
| clk_put(ce->clk); |
| } |
| |
| if (ce->con_id) |
| kfree(ce->con_id); |
| |
| kfree(ce); |
| } |
| |
| /** |
| * pm_runtime_clk_remove - Stop using a device clock for runtime PM. |
| * @dev: Device whose clock should not be used for runtime PM any more. |
| * @con_id: Connection ID of the clock. |
| * |
| * Remove the clock represented by @con_id from the list of clocks used for |
| * the runtime PM of @dev. |
| */ |
| void pm_runtime_clk_remove(struct device *dev, const char *con_id) |
| { |
| struct pm_runtime_clk_data *prd = __to_prd(dev); |
| struct pm_clock_entry *ce; |
| |
| if (!prd) |
| return; |
| |
| mutex_lock(&prd->lock); |
| |
| list_for_each_entry(ce, &prd->clock_list, node) { |
| if (!con_id && !ce->con_id) { |
| __pm_runtime_clk_remove(ce); |
| break; |
| } else if (!con_id || !ce->con_id) { |
| continue; |
| } else if (!strcmp(con_id, ce->con_id)) { |
| __pm_runtime_clk_remove(ce); |
| break; |
| } |
| } |
| |
| mutex_unlock(&prd->lock); |
| } |
| |
| /** |
| * pm_runtime_clk_init - Initialize a device's list of runtime PM clocks. |
| * @dev: Device to initialize the list of runtime PM clocks for. |
| * |
| * Allocate a struct pm_runtime_clk_data object, initialize its lock member and |
| * make the @dev's power.subsys_data field point to it. |
| */ |
| int pm_runtime_clk_init(struct device *dev) |
| { |
| struct pm_runtime_clk_data *prd; |
| |
| prd = kzalloc(sizeof(*prd), GFP_KERNEL); |
| if (!prd) { |
| dev_err(dev, "Not enough memory fo runtime PM data.\n"); |
| return -ENOMEM; |
| } |
| |
| INIT_LIST_HEAD(&prd->clock_list); |
| mutex_init(&prd->lock); |
| dev->power.subsys_data = prd; |
| return 0; |
| } |
| |
| /** |
| * pm_runtime_clk_destroy - Destroy a device's list of runtime PM clocks. |
| * @dev: Device to destroy the list of runtime PM clocks for. |
| * |
| * Clear the @dev's power.subsys_data field, remove the list of clock entries |
| * from the struct pm_runtime_clk_data object pointed to by it before and free |
| * that object. |
| */ |
| void pm_runtime_clk_destroy(struct device *dev) |
| { |
| struct pm_runtime_clk_data *prd = __to_prd(dev); |
| struct pm_clock_entry *ce, *c; |
| |
| if (!prd) |
| return; |
| |
| dev->power.subsys_data = NULL; |
| |
| mutex_lock(&prd->lock); |
| |
| list_for_each_entry_safe_reverse(ce, c, &prd->clock_list, node) |
| __pm_runtime_clk_remove(ce); |
| |
| mutex_unlock(&prd->lock); |
| |
| kfree(prd); |
| } |
| |
| /** |
| * pm_runtime_clk_acquire - Acquire a device clock. |
| * @dev: Device whose clock is to be acquired. |
| * @con_id: Connection ID of the clock. |
| */ |
| static void pm_runtime_clk_acquire(struct device *dev, |
| struct pm_clock_entry *ce) |
| { |
| ce->clk = clk_get(dev, ce->con_id); |
| if (IS_ERR(ce->clk)) { |
| ce->status = PCE_STATUS_ERROR; |
| } else { |
| ce->status = PCE_STATUS_ACQUIRED; |
| dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id); |
| } |
| } |
| |
| /** |
| * pm_runtime_clk_suspend - Disable clocks in a device's runtime PM clock list. |
| * @dev: Device to disable the clocks for. |
| */ |
| int pm_runtime_clk_suspend(struct device *dev) |
| { |
| struct pm_runtime_clk_data *prd = __to_prd(dev); |
| struct pm_clock_entry *ce; |
| |
| dev_dbg(dev, "%s()\n", __func__); |
| |
| if (!prd) |
| return 0; |
| |
| mutex_lock(&prd->lock); |
| |
| list_for_each_entry_reverse(ce, &prd->clock_list, node) { |
| if (ce->status == PCE_STATUS_NONE) |
| pm_runtime_clk_acquire(dev, ce); |
| |
| if (ce->status < PCE_STATUS_ERROR) { |
| clk_disable(ce->clk); |
| ce->status = PCE_STATUS_ACQUIRED; |
| } |
| } |
| |
| mutex_unlock(&prd->lock); |
| |
| return 0; |
| } |
| |
| /** |
| * pm_runtime_clk_resume - Enable clocks in a device's runtime PM clock list. |
| * @dev: Device to enable the clocks for. |
| */ |
| int pm_runtime_clk_resume(struct device *dev) |
| { |
| struct pm_runtime_clk_data *prd = __to_prd(dev); |
| struct pm_clock_entry *ce; |
| |
| dev_dbg(dev, "%s()\n", __func__); |
| |
| if (!prd) |
| return 0; |
| |
| mutex_lock(&prd->lock); |
| |
| list_for_each_entry(ce, &prd->clock_list, node) { |
| if (ce->status == PCE_STATUS_NONE) |
| pm_runtime_clk_acquire(dev, ce); |
| |
| if (ce->status < PCE_STATUS_ERROR) { |
| clk_enable(ce->clk); |
| ce->status = PCE_STATUS_ENABLED; |
| } |
| } |
| |
| mutex_unlock(&prd->lock); |
| |
| return 0; |
| } |
| |
| /** |
| * pm_runtime_clk_notify - Notify routine for device addition and removal. |
| * @nb: Notifier block object this function is a member of. |
| * @action: Operation being carried out by the caller. |
| * @data: Device the routine is being run for. |
| * |
| * For this function to work, @nb must be a member of an object of type |
| * struct pm_clk_notifier_block containing all of the requisite data. |
| * Specifically, the pwr_domain member of that object is copied to the device's |
| * pwr_domain field and its con_ids member is used to populate the device's list |
| * of runtime PM clocks, depending on @action. |
| * |
| * If the device's pwr_domain field is already populated with a value different |
| * from the one stored in the struct pm_clk_notifier_block object, the function |
| * does nothing. |
| */ |
| static int pm_runtime_clk_notify(struct notifier_block *nb, |
| unsigned long action, void *data) |
| { |
| struct pm_clk_notifier_block *clknb; |
| struct device *dev = data; |
| char **con_id; |
| int error; |
| |
| dev_dbg(dev, "%s() %ld\n", __func__, action); |
| |
| clknb = container_of(nb, struct pm_clk_notifier_block, nb); |
| |
| switch (action) { |
| case BUS_NOTIFY_ADD_DEVICE: |
| if (dev->pwr_domain) |
| break; |
| |
| error = pm_runtime_clk_init(dev); |
| if (error) |
| break; |
| |
| dev->pwr_domain = clknb->pwr_domain; |
| if (clknb->con_ids[0]) { |
| for (con_id = clknb->con_ids; *con_id; con_id++) |
| pm_runtime_clk_add(dev, *con_id); |
| } else { |
| pm_runtime_clk_add(dev, NULL); |
| } |
| |
| break; |
| case BUS_NOTIFY_DEL_DEVICE: |
| if (dev->pwr_domain != clknb->pwr_domain) |
| break; |
| |
| dev->pwr_domain = NULL; |
| pm_runtime_clk_destroy(dev); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| #else /* !CONFIG_PM_RUNTIME */ |
| |
| /** |
| * enable_clock - Enable a device clock. |
| * @dev: Device whose clock is to be enabled. |
| * @con_id: Connection ID of the clock. |
| */ |
| static void enable_clock(struct device *dev, const char *con_id) |
| { |
| struct clk *clk; |
| |
| clk = clk_get(dev, con_id); |
| if (!IS_ERR(clk)) { |
| clk_enable(clk); |
| clk_put(clk); |
| dev_info(dev, "Runtime PM disabled, clock forced on.\n"); |
| } |
| } |
| |
| /** |
| * disable_clock - Disable a device clock. |
| * @dev: Device whose clock is to be disabled. |
| * @con_id: Connection ID of the clock. |
| */ |
| static void disable_clock(struct device *dev, const char *con_id) |
| { |
| struct clk *clk; |
| |
| clk = clk_get(dev, con_id); |
| if (!IS_ERR(clk)) { |
| clk_disable(clk); |
| clk_put(clk); |
| dev_info(dev, "Runtime PM disabled, clock forced off.\n"); |
| } |
| } |
| |
| /** |
| * pm_runtime_clk_notify - Notify routine for device addition and removal. |
| * @nb: Notifier block object this function is a member of. |
| * @action: Operation being carried out by the caller. |
| * @data: Device the routine is being run for. |
| * |
| * For this function to work, @nb must be a member of an object of type |
| * struct pm_clk_notifier_block containing all of the requisite data. |
| * Specifically, the con_ids member of that object is used to enable or disable |
| * the device's clocks, depending on @action. |
| */ |
| static int pm_runtime_clk_notify(struct notifier_block *nb, |
| unsigned long action, void *data) |
| { |
| struct pm_clk_notifier_block *clknb; |
| struct device *dev = data; |
| char **con_id; |
| |
| dev_dbg(dev, "%s() %ld\n", __func__, action); |
| |
| clknb = container_of(nb, struct pm_clk_notifier_block, nb); |
| |
| switch (action) { |
| case BUS_NOTIFY_BIND_DRIVER: |
| if (clknb->con_ids[0]) { |
| for (con_id = clknb->con_ids; *con_id; con_id++) |
| enable_clock(dev, *con_id); |
| } else { |
| enable_clock(dev, NULL); |
| } |
| break; |
| case BUS_NOTIFY_UNBOUND_DRIVER: |
| if (clknb->con_ids[0]) { |
| for (con_id = clknb->con_ids; *con_id; con_id++) |
| disable_clock(dev, *con_id); |
| } else { |
| disable_clock(dev, NULL); |
| } |
| break; |
| } |
| |
| return 0; |
| } |
| |
| #endif /* !CONFIG_PM_RUNTIME */ |
| |
| /** |
| * pm_runtime_clk_add_notifier - Add bus type notifier for runtime PM clocks. |
| * @bus: Bus type to add the notifier to. |
| * @clknb: Notifier to be added to the given bus type. |
| * |
| * The nb member of @clknb is not expected to be initialized and its |
| * notifier_call member will be replaced with pm_runtime_clk_notify(). However, |
| * the remaining members of @clknb should be populated prior to calling this |
| * routine. |
| */ |
| void pm_runtime_clk_add_notifier(struct bus_type *bus, |
| struct pm_clk_notifier_block *clknb) |
| { |
| if (!bus || !clknb) |
| return; |
| |
| clknb->nb.notifier_call = pm_runtime_clk_notify; |
| bus_register_notifier(bus, &clknb->nb); |
| } |